execution: add ExecutionEngine tests (#2095)

Author: JacekGlen

silkworm/capi/silkworm_test.cpp

@@ -41,6 +41,7 @@ namespace snapshot_test = snapshots::test_util;
 struct CApiTest : public db::test_util::TestDatabaseContext {
     TemporaryDirectory tmp_dir;
     SilkwormSettings settings{.log_verbosity = SilkwormLogLevel::SILKWORM_LOG_NONE};
+    mdbx::env_managed& db{get_mdbx_env()};
 };
 
 //! Utility to copy `src` C-string to `dst` fixed-size char array

silkworm/db/test_util/test_database_context.cpp

@@ -188,6 +188,12 @@ namespace {
 
 }  // namespace
 
-TestDatabaseContext::TestDatabaseContext() : db{initialize_test_database()} {}
+TestDatabaseContext::TestDatabaseContext() : db_{initialize_test_database()} {}
+
+silkworm::ChainConfig TestDatabaseContext::get_chain_config() {
+    db::ROTxnManaged txn{db_};
+    auto chain_config = db::read_chain_config(txn);
+    return chain_config ? *chain_config : silkworm::ChainConfig{};
+}
 
 }  // namespace silkworm::db::test_util

silkworm/db/test_util/test_database_context.hpp

@@ -34,12 +34,18 @@ class TestDatabaseContext {
     TestDatabaseContext();
 
     ~TestDatabaseContext() {
-        auto db_path = db.get_path();
-        db.close();
+        auto db_path = db_.get_path();
+        db_.close();
         std::filesystem::remove_all(db_path);
     }
 
-    mdbx::env_managed db;
+    mdbx::env_managed& get_mdbx_env() { return db_; }
+    db::EnvConfig get_env_config() { return env_config_; }
+    silkworm::ChainConfig get_chain_config();
+
+  private:
+    mdbx::env_managed db_;
+    db::EnvConfig env_config_;
 };
 
 }  // namespace silkworm::db::test_util